1. Field of the Invention
This invention relates to motorized pumps and stoppers which may be used for pressurizing and/or evacuating food or drink containers and, in particular, to a motorized vacuum/pressure pump which employs a piston drive mechanism to convert rotary motion of a motor to a reciprocating motion of a piston and a valve selectable to change the pump between vacuum and pressure pumping modes, and a stopper which may be switched between pour and vacuum/pressure seal positions. The pump may be incorporated into a container lid.
2. Description of Related Art
A combination vacuum/pressure pump for preserving wine and/or foods under vacuum, and pressurizing carbonated drinks and other foods, is disclosed in U.S. Pat. No. 5,031,785. This pump utilizes a hand-pumping mechanism, switchable between vacuum and pressure modes, and mates with a valve stopper, likewise switchable between vacuum and pressure modes, that is disposed in the open mouth of a food or drink container. While this combination vacuum/pressure pump is quite useful, it requires the user to open the pump head to switch between the vacuum and pressure pumping modes. A more convenient vacuum/pressure switching method would be useful. Also, it would be useful to have a vacuum/pressure pump which does not require hand-pumping operation.
The '785 patent also discloses a stopper for use with the vacuum/pressure pump, which has a valve element that may be reversed between vacuum and pressure sealing positions. However, in order to access the contents of the food or drink container, the stopper must be removed from the mouth of the container. It would be useful to provide a way to access the contents of the container without having to remove the stopper.
Another vacuum pump and stopper system employs an audible click when the system reaches a desired level of vacuum, relying on a mechanical system to generate the sound. It would be useful to have an indicator in both a vacuum and pressure system that provides a reliable indicator, not limited to a sound, to indicate when the desired level of vacuum or pressure has been achieved.
Some foods or drinks that are preferably stored at a vacuum also are provided in containers that cannot be closed with bottle stoppers, such as coffee in conventional one-pound containers. It would be desirable to have a way to automatically seal and store the contents of such containers in a vacuum.
Moreover, it is important in vacuum/pressure pump and stopper systems to utilize one-way valves that are inexpensive to manufacture, yet seal properly.